18881018 has 16 divisors (see below), whose sum is σ = 30687720. Its totient is φ = 8712288.

The previous prime is 18881017. The next prime is 18881021. The reversal of 18881018 is 81018881.

It can be written as a sum of positive squares in 4 ways, for example, as 877969 + 18003049 = 937^2 + 4243^2 .

It is not an unprimeable number, because it can be changed into a prime (18881011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2246 + ... + 6542.

Almost surely, 2^18881018 is an apocalyptic number.

18881018 is a deficient number, since it is larger than the sum of its proper divisors (11806702).

18881018 is an equidigital number, since it uses as much as digits as its factorization.

18881018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4338 (or 4312 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 35.

The square root of 18881018 is about 4345.2293380212. The cubic root of 18881018 is about 266.2819950236.

Adding to 18881018 its reverse (81018881), we get a palindrome (99899899).

The spelling of 18881018 in words is "eighteen million, eight hundred eighty-one thousand, eighteen".